KR960004418B1 - Method and apparatus for continuous casting - Google Patents

Abstract

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Description

Continuous casting method and apparatus

1 is a longitudinal sectional view of a horizontal continuous casting machine embodying the principles of the present invention.

FIG. 2 is a longitudinal sectional view of a sealing mechanism at the inlet end of the mold shown in FIG.

3 is a longitudinal sectional view of the closure mechanism at the outlet end of the mold shown in FIG.

4 is a longitudinal sectional view of another sealing mechanism at the inlet end of the mold shown in FIG.

5 is a longitudinal sectional view of another horizontal continuous casting machine embodying the principles of the present invention.

6 is a longitudinal sectional view of the sealing mechanism at the inlet end of the mold shown in FIG.

FIG. 7 is a longitudinal sectional view of a closure mechanism assigned between two adjacent molds shown in FIG.

FIG. 8 is a longitudinal sectional view of another closure mechanism disposed between two adjacent molds shown in FIG.

9 is a cross-sectional view showing a first mold and a peripheral mechanism of a continuous square billet casting machine incorporating the principles of the present invention.

10 is a detailed front view of a second mold disposed beside the first mold shown in FIG.

11 is a sectional view showing a first mold and a peripheral device of another continuous square billet casting machine incorporating the principles of the present invention;

12 is a cross-sectional view of a partially deformed closure mechanism disposed between the tundish and the mold.

13 is a longitudinal sectional view of another partially deformed closure mechanism disposed between the tundish and the mold.

14 is a longitudinal sectional view of an intermediate ring partially covered with a seal.

15 is a longitudinal sectional view of an intermediate ring covered with a sealing material.

16 is a longitudinal sectional view of another partially closed mechanism of the vertical continuous casting machine.

The present invention relates to a continuous casting method and apparatus, and more particularly, to a continuous casting method and apparatus in which molten metal is continuously supplied to a cooled cylindrical mold, wherein the casting part solidifies under the surface of the molten metal. Is formed, and then the formed casting is removed from the mold.

The method and apparatus of the present invention can be applied to continuous casting of billets of carbon steel, stainless steel and other metals and other forms.

Horizontal continuous casting is one of the known methods of solidifying molten metal continuously supplied to a cooled cylindrical mold under the molten metal surface. In horizontal continuous casting, the brake ring provided at the inlet of the mold stabilizes the start of metal solidification.

The brake ring has a circumferential step that protrudes into the mold, the inner diameter of which is greater than the inner diameter of the circumferential step. For example, in order to keep the brake ring in close contact with the mold, the mating surfaces are tapered and pressed together. Molten metal in the mold begins to solidify in a region adjacent to the periphery of the brake ring front end (which is downstream of the metals) and withdraws intermittently through the outlet end of the mold as the solidification shell grows.

Bubbles are often formed in the subsurface portion of the part cast by the method. There are many reasons for this. For example, even when the brake ring is pressed against the mold as described above, the gap may occur as a result of thermal expansion or other causes. Since the ferrostatic pressure of the molten metal is higher than atmospheric pressure in the brake ring where solidification is initiated, air does not penetrate near the brake ring causing metal solidification to start under the surface of the molten metal.

However, when the coagulation shell is withdrawn and separated from the front end of the brake ring, there is almost no vacuum between the front end of the brake ring and the rear end of the coagulation shell, which faces the front end of the brake ring, although for a short time. A formed gap is formed.

Air then penetrates into the gap from the outside of the brake ring through a hole between the brake ring and the contact surface of the mold and also into the molten metal to form bubbles.

Occasionally, air penetrating from the outlet end of the mold penetrates into the gap and molten metal through the hole between the brake ring and the mold to form bubbles.

Bubbles are formed in an area of 2 mm to 3 mm below the surface of the casting part.

When subsequently rolled up, the bubbles in the casting create several surface defects such as seams and longitudinal cracks. The resulting surface defects are particularly fatal in stainless steel and other products that must meet stringent surface quality requirements.

Therefore, bubbles must be removed by scarfing or other surface treatment methods, which increase the manufacturing cost and lower the production yield.

Japanese Utility Model Publication No. 89-38136 discloses a technique for fixing a brake ring in a manner to prevent infiltration of air. With this technique, the joint between the brake ring and the molten metal cooling member (mould) is sealed by airtight annular gaskets. However, when the annular gasket is heated by, for example, heat from the mold, the annular gasket is deteriorated beyond the temperature it can withstand.

Damaged annular gaskets lose their sealing function and as a result air penetrates into the mold, forming bubbles in the solidification shell.

US 4,817,701 discloses a continuous casting technique for sealing molten metal supply nozzles and mold inlets with an inert gas that does not react with molten metal.

The purpose of this technique is to completely prevent the penetration of gases in the atmosphere that oxidizes the surface of molten metal. However, even with the present technology, there is no risk of bubbles in the casting part.

By analyzing the gas contained in the bubbles formed to reveal the cause of the bubble formation, the inventors found that the gas in the bubble mainly consists of argon, and the metal around the bubble shows higher nitrogen content than other parts.

These studies suggest that nitrogen in the air dissolves in the molten metal, but argon, which is insoluble in the molten metal, remains as a bubble.

In order to confirm the estimated fact, continuous casting test was carried out by supplying inert argon gas into the shielding device surrounding the periphery of the brake ring as in the US patent technique. In this test, more bubbles were formed in the subsurface of the casting than in the conventional continuous casting process without using argon.

However, bubbles were not formed when nitrogen soluble in molten metal was supplied in place of insoluble argon. The present invention is based on the above-mentioned studies.

Japanese Laid-Open Patent Publication No. 86-71157 discloses a horizontal continuous casting technique using a cylindrical mold in which nitrogen is supplied to a part of the corner member, wherein the corner member protrudes inward from the inner surface of the cylindrical mold. The refractory board is placed under the axis of the cylindrical mold. This technique uniformly cools the entire surface of the solidification shell by moving downstream where the molten metal contacts the inner surface of the mold.

However, by introducing nitrogen gas only into the lower portion of the corner member, this technique does not prevent air from penetrating into the mold through the entire circumference of the junction where the brake ring and the inner surface of the mold contact.

It is an object of the present invention to provide a method for continuous casting of an improved quality casting, which prevents penetration of argon gas and other gases insoluble in molten metal and the formation of bubbles in the casting by not exposing the molten metal to the atmosphere and To provide a device.

The method and apparatus according to the present invention prevent exposure of the molten metal to the atmosphere by supplying a closed gas soluble in the molten metal to a location where air intrusion into the mold is likely to occur. Mild gas soluble in molten metal does not remain as bubbles in the casting.

This eliminates the need to remove bubbles from the casting, thereby making it possible to produce high quality rolled material free of surface defects at low cost.

The method and apparatus of the present invention; (a) continuously supplying molten metal from a tundish to a cooling mold having an inlet and an outlet through at least a brake ring; and (b) continuously cooling the molten metal in the mold to melt under the surface of the molten metal. Forming a casting by causing solidification of the metal to initiate, (c) withdrawing the casting intermittently with respect to the mold from the outlet of the mold, and (d) a gap between the mold and the contact surface of the brake ring from the outside of the mold inlet. Operating steps such as constantly supplying a closed gas soluble in molten metal at a pressure higher than atmospheric pressure to fill the entire gap between the mold and the casting part from the outside of the whole and / or mold outlet.

A cut-off space bounded by a closed curve whose diameter is larger than the maximum diameter of the contact surface of the mold and the brake ring will be continuously provided at the mold inlet.

In order to prevent air from penetrating into the mold through the gap between the contact surfaces, a closed gas soluble in molten metal is constantly supplied into this blocking space at a pressure above atmospheric pressure. The blocking space may be divided into two spaces which are completely isolated while the closed gas is supplied to the outer blocking space and the inner blocking space is maintained at a pressure lower than atmospheric pressure. Furthermore, another blocking space may be provided at the outlet side of the mold, in which the same closed gas soluble in molten metal is constantly supplied at a pressure higher than atmospheric pressure. The blocking space at the inlet end is maintained at a pressure lower than atmospheric pressure, and the blocking space at the outlet end is provided with a closed gas soluble in molten metal, and a blocking space may be provided at the inlet and outlet ends of the mold, respectively.

Horizontal continuous casting machine is a kind of continuous casting machine which forms the solidification shell by starting solidification of metal under the surface of molten metal in the mold and withdraws the casting part thus obtained from the mold.

1 shows a horizontal continuous circular billet casting machine.

As shown, the tundish nozzle 12 and the mold 24 at the bottom of the tundish 10 are connected to each other via the intermediate ring 18 and the brake ring 22. The castable refractory material 13 is fixedly installed between the tundish nozzle 12 and the intermediate ring 18. The tundish 10, tundish nozzle 12, and intermediate ring 18 are made of ordinary zircon- or alumina-refractory.

The brake ring 22 is pressed against the inlet of the mold 24 and the intermediate ring 18 is fixed to the mold with a metal fastener 20. The brake ring 22 is made of a heat resistant ceramic containing boron ignition, silicon nitride and the like. The mold 24 is made of copper and fixed to the housing 27 with a retaining ring 28. The coolant supply pipe 29 and the coolant discharge pipe 30 are connected to the housing 27 so that the coolant circulated through the housing 27 cools the mold 24.

In order to support the annular gasket 32, an annular gasket groove 31 is provided at the front end and the rear end of the housing 27, respectively. The intermediate ring 18, the brake ring 22, the mold 24, and the housing 27 may be integrally connected to and disconnected from the tundish 10.

Molten metal M is supplied from the tundish 10 to the mold through the tundish nozzle 12, the intermediate ring 18, and the brake ring 22. The molten metal (M) is cooled by the inner surface of (24) to form a solidified shell (S). The solidification shell S begins to form in the brake ring 22.

The brake ring 22 prevents the solidification shell S from growing in the opposite direction, that is, toward the middle ring 18. The molten metal M is ejected from the inlet of the mold 24 by the intermittently rotating pinch rolls 56 of the casting part C in which the molten metal M is solidified. The casting part C for the mold has a gap between the brake ring 22 and the solidification shell S due to the intermittent exit. Molten metal M then penetrated into the gap forms a new solidification shell S. Intermittent withdrawal of casting portion C relative to mold 24 is performed by vacuuming mold 24 in the retracting direction while continuing to rotate pinch roll 56.

As described above, from the outside of the mold ring through the gap between the brake ring 22 and the mold 24 from the outside of the brake ring 22 and through the gap between the casting part C and the mold 24. Air penetrates into the gap between the brake ring and the solidification shell and is trapped in the molten metal (M) to form bubbles. In order to prevent air from penetrating, the preferred embodiment described is provided with the closure mechanism shown in FIGS. 1 to 3.

As shown in FIG. 1 and FIG. 2, the annular gasket groove 33 is dug in the inlet end surface of the mold 24 to accommodate the annular gasket 34 which is a silicone rubber (deteriorated at about 250 ° C). The annular gasket 34 inserted between the flange surface of the intermediate ring 18 and the inlet end surface of the mold 24 forms an annular blocking space on the outside of the brake ring 22.

Another annular gasket 35 is inserted between the outer circumference of the intermediate ring 18 and the inner surface of the retaining ring 28 to double seal the outside of the brake ring 22.

This multiple seal provides a tight seal.

The closed gas supply passage 38 is installed in the flange 25 of the mold 24.

The closed gas supply passage 38 is opened in the annular gasket groove 33 and connected to the blocking space 36. The closed gas supply pipe 39, which is in turn connected to the nitrogen gas cylinder 40 through the pressure regulating valve 41, is connected to the inlet of the closed gas supply passage 38.

As shown in FIG. 1 and FIG. 3, the annular sealing box 44 is attached to the outlet end of the mold 24. As shown in FIG. The box has a sleeve 45, the inside of which is lined with graphite 46, and the casting part C passes through the sleeve part 45. As shown in FIG.

The annular gasket groove 48 is dug on the surface of the flange of the annular hermetic box 44 facing the outlet end surface of the mold 24. The annular gasket 49 is inserted into the annular gasket groove 48, whereby the annular gasket blocking space 51 surrounding the casting part C is formed in the flange 47. The closed gas supply passage 53 is provided in the flange 47. The closed gas supply passage 53 is open to the annular gasket groove 48 and is connected to the blocking space 51.

The closed gas supply pipe 54, which is in turn connected to the nitrogen gas cylinder 40 through the pressure control valve 55, is connected to the inlet of the closed gas supply passage 53.

In the above-mentioned closed mechanism, the pressure regulating valves 41 and 55 are lowered from the nitrogen gas cylinder 40 to the intermediate ring 18 and the mold 24 after the pressure is lowered to almost 5 to 6 kgf / cm 2, which is a value higher than the ambient atmospheric pressure. Nitrogen gas is supplied to the blocking space 36 in between and the blocking space 51 in the sealed box 44. Although nitrogen gas initially has a pressure above atmospheric pressure as described above, the nitrogen pressure is considerably lowered because of resistance in the passage when nitrogen gas reaches the brake ring 22 in the mold 24. The initial pressure of the nitrogen gas is set so that the gas pressure does not exceed the ferrostatic pressure of the molten metal M in the vicinity of the brake ring 22 in the mold.

Since nitrogen gas is maintained at a pressure above atmospheric pressure in the blocking spaces 36 and 51, argon in the atmosphere cannot penetrate into the mold 24. Furthermore, since the pressure of the nitrogen gas in the vicinity of the brake ring 22 in the mold 24 is maintained below the ferrostatic pressure of the molten metal M, the nitrogen gas is not flowed back from the tundish 10 but is ejected. It doesn't work.

Nitrogen gas is dissolved in the molten metal (M) and does not remain as bubbles in the casting (C).

Even when nitrogen gas leaks into the mold 24, the sleeve 45, or the atmosphere, the blocking spaces 36 and 51 are always automatically filled with nitrogen gas automatically replenished from the nitrogen gas cylinder 40.

Although nitrogen gas is the most preferred closed gas soluble in molten metal, one or more gases may be selected from the group consisting of carbon monoxide, carbon dioxide, hydrogen, methane, propane and ammonia.

4 shows a simplified example of a closure mechanism at the inlet end of a mold different from that shown in FIG. 2 in that no blocking space is provided.

The annular space 37 is formed between the brake ring 22 and the retaining ring 28 but is not sealed with a gasket or other device. A radially extending closed gas supply passage 38 whose inlet end is connected to the closed gas supply pipe 39 is provided in the fixing ring 28. Since the annular space 37 is not completely isolated from the atmosphere, the pressure of the nitrogen gas supplied thereto is set to about 6 to 10 kgf / cm 2, which is larger than the atmospheric pressure, which is higher than the pressure in the closed mechanism shown in FIG. high.

Similarly, an annular space filled with high pressure nitrogen gas that is not sealed may be formed at the outlet side of the mold.

5 to 7 show another preferred embodiment of the present invention.

In the following description, the same members as those of the preferred embodiment shown in FIG. 1 are denoted by the same member numbers without detailed description thereof.

The horizontal continuous casting machine shown in FIG. 5 includes a first mold 57 and a second mold 61. The tundish nozzle 12 is connected to the first mold 57 through the sliding gate 15, the intermediate ring 84, and the brake ring 22. The sliding gate 15 is made of ordinary zircon- or alumina-refractory, such as a tundish 10 or the like. The first mold 57 is the same as the mold 24 in the most preferred embodiment described above. The second mold 61 is an adjustable mold composed of four mold segments 62 divided into four circumferences, and the segment is lined with graphite 63 inside. The support frame 66, the link mechanism 68 and the guide sleeve 71 are attached to the outlet end of the first mold 57. The front end of each mold member 62 is connected to the link mechanism 68, and the link mechanism 68 is guided by the guide sleeve 71. As shown in FIG.

The spring shaft 73 penetrates the rear end of the support frame 66.

One end of the spring shaft 73 is pinned to each mold member 62 and the other end is screwed with an adjustment nut 76. The coil spring 78 is inserted between the support frame 66 and the adjustment nut 76. Four hydraulic cylinders 80 are provided in the center of the support frame 66, and the hemispherical holder 82 is provided at the tip of the piston rod 81. As shown in FIG.

The holder 82 in the piston rod 81 fits into the shallow spherical recess 64 in each mold member 62. When the pressurized fluid is supplied to the hydraulic cylinder 80, the force for tilting each mold member 62 near the pin 70 of the link mechanism 68 against the spring force of the coil spring 78 is respectively applied. Is applied to the mold member 62. The tilting of the mold segment 62 is automatically adjusted according to the extent to which the solidified casting part C shrinks.

The sealing mechanism will now be described below.

First, the closing mechanism at the inlet end of the first mold 57 will be described.

As shown in FIG. 5 and FIG. 6, the hollow cooling ring 88 made of steel is fitted on the intermediate ring 84 and bonded with cement. The hollow cooling ring 88 has a trapezoidal cross section and is ring-shaped. The inside of the hollow cooling ring 88 is divided by partitions (not shown).

In order to increase the cooling effect of the annular gaskets 94 and 98 and the vicinity thereof, the wide surface (front) of the longitudinal hole cooling ring 88 faces the inlet end of the first mold 57.

The intermediate ring holder 85 supports the rear surface of the hollow cooling ring 88.

The cooling air supply pipe 89 and the cooling air discharge pipe 90 are connected to the hollow cooling ring 88.

The cooling air supply pipe 89 and the cooling air discharge pipe 90 pass through the annular double wall 107 to be described later in a sealed state. A cooling device composed of a compressor, a cooler, a dehydrator, and the like is connected to a cooling air supply pipe 89. The cooling air supplied from the cooling air supply pipe 89 cools the hollow cooling ring 88 by substantially moving around the hollow cooling ring, and then is discharged into the atmosphere through the cooling air discharge pipe 90.

The annular gasket groove 93 is dug in the inlet end surface of the first mold 57 to support the annular gasket 94 made of silicone rubber fitted therein.

The annular gasket 94 supported between the front end of the hollow cooling ring 88 and the surface of the inlet end of the first mold 57 has a first annular cut-off space ＂a 외부 at the outer circumference of the brake ring 22. 95). The annular gasket 98 inserted between the outer surface of the hollow cooling ring 88 and the inner surface 28 of the fixing ring has a different first annular blocking space ＂b between the annular gasket 94 and the annular gasket 98. ＂(100) is formed.

The suction port 102 is provided in the flange 58 of the first mold 57.

The inlet 102 is open in the annular gasket groove 93 and is connected to the first blocking space ＂a＂ 95. The suction pipe 103 connected to the vacuum pump 104 is attached to the inlet of the suction port 102. The closed gas supply port 105 is provided in the flange 58 of the first mold 57. The closed gas supply port 105 is opened in the first blocking space ＂b ′ 100.

A hermetically sealed gas supply pipe 39 penetrating the annular double wall 107 to be described later in a hermetically sealed state is connected to an inlet portion of the hermetic gas supply port 105. The nitrogen gas cylinder 40 is connected to the closed gas supply pipe 39 through the pressure regulating valve 41.

The circumferential wall 106 is welded to the front end surface of the frame 16 of the sliding gate 15. The annular double wall 107 made of steel is welded to the housing 27 of the first mold 57 facing the frame 16 of the sliding gate 15 to form the gasket groove 108. A gasket 109 made of a kaowool is inserted into the gas groove 108.

The circumferential wall 106 and the annular double wall 107 form a second annular blocking space 111 therebetween. The nitrogen gas suction pipe 112 penetrates the circumferential wall 106 vertically. The nitrogen gas suction pipe 112 is connected to the nitrogen gas cylinder 40 through the pressure control valve 114.

At the outlet end of the first mold 57 just described, when the intermediate ring 84 and the first mold 57 in the closure mechanism are connected, the surface of the inlet end of the first mold 57 and the hollow cooling ring A desired amount of hermetic surface pressure is applied to the annular gasket 94 being pressed between the front ends of the ends.

The tundish 10, which is conveyed forward by a hydraulic cylinder (not shown), is connected to the molds 57 and 61 via a sliding gate 15 and an intermediate ring 84.

When the front end of the circumferential wall 106 comes into contact with the gasket 109, the inside of the second blocking space 111 is automatically sealed. This eliminates the need to seal the space between the sliding gate 15 and the first mold 57.

When the vacuum pump is operated, the vacuum pump 104 discharges the remaining air from the first blocking space 공간 a ＂95 to maintain lower than the first blocking space atmospheric pressure. The pressurized nitrogen gas is supplied from the nitrogen gas cylinder 40 to the first blocking space ＂b ′ 100 and the second blocking space 111. The high pressure nitrogen gas pressure in the nitrogen gas cylinder 40 is reduced to about 5 kgf / cm 2 higher than atmospheric pressure by the pressure regulating valves 41 and 114 before being supplied. Since the pressure of the nitrogen gas is higher than atmospheric pressure, air cannot flow into the sliding gate 15, the intermediate ring 84, and the first mold 57. Nitrogen gas dissolved in the casting part C to form a solid solution or flowed into the sliding gate 15 or elsewhere is automatically replenished from the nitrogen gas cylinder 40.

One sealing surface of the annular gasket 94 is in contact with the hollow cooling ring 88 and the other surface is in contact with the inlet end surface of the water-cooled first mold 57. Therefore, the annular gasket 94 is maintained below the limit temperature. Thus, the annular gasket 94 remains unthermally degraded to maintain its original sealing function. When the actual temperature of the hollow cooling ring 88 was measured, the maximum temperature near the annular gasket was about 200 ° C., lower than 230 ° C., which is the limit temperature that the annular gasket made of silicon rubber can withstand.

In the above sealing mechanism, the circumferential wall 106 and the double wall 107 replace the intermediate ring 84 and the brake ring 22 with the sliding gate 15, the intermediate ring 84, and the brake ring 22. Can surround. In this arrangement, the circumferential wall 106 is attached to the steel shell 11 of the tundish 10.

The circumferential wall 106 may also be attached to the housing of the first mold instead of the frame of the sliding gate 15. In this arrangement, an annular gasket 108 is attached to the frame 16 of the sliding gate 15.

Now, the closure mechanism between the first mold 57 and the second mold 61 will be described.

As shown in Figs. 5 and 7, the annular gasket groove 116 is dug in the plane of the outlet end of the first mold 57 and the annular gasket 117 is inserted therein.

In addition, the annular nitrogen gas supply groove 118 through the second mold 61 is dug in the inlet end of the second mold. The inlet end surface of the second 'mould 61 in contact with the annular gasket 117 seals the nitrogen gas supply groove 118. The closed gas supply port 119 is provided near the inlet portion of the second mold 61. The closed gas supply port 119 is open to the nitrogen gas supply groove 118. The closed gas supply pipe 120 is attached to the inlet of the closed gas supply port 119.

The closed gas supply pipe 120 is connected to the nitrogen gas cylinder 40 through the pressure control valve 121.

In the above-described closed mechanism, nitrogen gas is supplied from the nitrogen gas cylinder 40 to the nitrogen gas supply groove 118 while being decompressed by the pressure regulating valve 121 at about 5 to 6 kgf / cm 2 higher than atmospheric pressure. . Since the nitrogen gas pressure in the nitrogen gas supply groove 118 is higher than atmospheric pressure, air cannot flow into the first mold 57 and the second mold 61. Even when nitrogen gas flows into the molds 57 and 61, the nitrogen gas supply groove 118 is always automatically filled with nitrogen gas that is automatically replenished from the nitrogen gas cylinder 40.

FIG. 8 shows a simplified variant of the closure mechanism between the first mold 57 and the second mold 61 shown in FIG. 7. The simplified closure mechanism differs from that shown in FIG. 7 in that it does not have a blocking space. An annular nitrogen gas supply groove 118 is provided on the inlet end surface of the second mold 61, while the annular space 122 is formed between the first mold 57 and the first mold 61. The annular space 122 is sealed with a gasket or other material. The annular space 122 is connected to the closed gas supply port 119 installed in the mold member 62 and the closed gas supply pipe 120 is connected to the inlet of the closed gas supply port 119.

Since the annular space 122 is not completely disconnected from the atmosphere, the pressure of the nitrogen gas supplied thereto is set at about 6 to 10 kgf / cm 2 or more above atmospheric pressure at a higher pressure than that of the closed mechanism shown in FIG.

The second preferred embodiment described above is a round billet casting machine.

Now let's describe the square billet casting machine.

As shown in FIG. 9, the annular gasket 123 made of silicon rubber is inserted and fixed between the housing of the first mold 57 and the second mold in a manner surrounding the casting part C. As shown in FIG.

As shown in FIG. 10, the second mold 125 has four sidewall blocks 126 each holding a plate of graphite 127 and four adjacent ones between the adjacent sidewall blocks 126. As shown in FIG. It is comprised by the corner block 129. The side block 126 and the corner block 129 are made of steel and secured to the holding frame by the same device as in the preferred control embodiment. The coolant passage 131 is provided at the side wall block 126 and the corner block 129. Each corner block 129 has a nitrogen gas inlet 132 penetrating the corner block perpendicular to the cooling water passage 131. The nitrogen gas supply pipe 133 is connected to the inlet of the nitrogen gas inlet 132. The nitrogen gas supply pipe 133 is connected to the nitrogen gas cylinder 134 through the pressure regulating valve 135. The high pressure nitrogen gas is supplied to the nitrogen gas inlet 132 from the nitrogen gas cylinder 134 while reducing the pressure thereof to about 5 to 6 kgf / cm 2 higher than atmospheric pressure by the pressure regulating valve 135.

In the case where pressurized nitrogen gas is supplied from the nitrogen gas cylinder 134 to the corner block 129 in the above-described mold junction sealing mechanism, a part of the gas penetrates into the first mold 57 and the other part of the second mold It penetrates into 125 and flows into the gap g between the inner wall of the mold and the solidification shell S. Since the pressure of nitrogen gas is higher than atmospheric pressure, air does not flow into the gap. Nitrogen gas consumed by dissolving in the casting part C to form a solid solution or flowing out through the inlet of the first mold 57 or the outlet of the second mold 125 is automatically discharged from the nitrogen gas cylinder 134. Is replenished.

FIG. 11 shows a simplified variant of the closure mechanism between the first mold 57 and the second mold 125 shown in FIG. The simplified closure mechanism differs from that shown in FIG. 9 in that it does not have a blocking space. That is, the outlet end surface of the first mold 57 and the inlet end surface of the second mold 125 are in direct contact with each other, and there is no annular gasket inserted therebetween. The nitrogen gas inlet 132 is provided at each corner block 129 of the second mold 125, and the nitrogen supply pipe 133 is connected to the inlet of the nitrogen gas inlet 132. Since the junction between the first mold 57 and the second mold 125 is not completely isolated from the atmosphere, the pressure of the nitrogen gas supplied thereto is higher than the atmospheric pressure higher than in the case of the closed mechanism shown in FIG. It is set at about 6 to 10 kgf / cm 2.

We will now describe some partial variations of the closure mechanism installed at the inlet end of the mold.

In the modification shown in FIG. 12, the two annular gaskets 139 are inserted radially double in the annular gasket groove 138 which is dug in the flange 25 of the mold 24. As shown in FIG.

The double closure mechanism with two annular gaskets 139 prevents air from penetrating more effectively. A circumferential groove 142 concentric with the inner surface of the intermediate ring 141 is dug into its exit end surface. The circumferential groove 142 is inside the annular gasket 138.

Heat conducted from the inside of the intermediate ring 141 to which the molten metal is in contact with the outside thereof is diverted along the circumference of the circumferential groove 142. This adjusts the temperature increase of the annular gasket 139 to prevent it from overheating.

13 is a modification in which the annular gasket 148 is inserted between the tundish 10 and the mold 24. This seal is used for smaller continuous casting machines.

The tundish 10 and the mold 24 are only connected to the tundish nozzle 12, the brake ring 22 and the heat resistant gasket 144. The annular gasket 148 is inserted between the tundish 10 and the mold 24 which are not spaced apart by the connecting member. The annular protrusion 145 is formed in the steel shell 11 in front of the tundish 10. The annular gasket 147 is dug on the outer circumferential surface of the flange 25 of the mold 24 and the annular gasket 148 is inserted therein.

The annular gasket 148 is fitted to the annular projection 145.

The heat-resistant gas 144 is tack-welded in front of the tundish nozzle 12, while the brake ring 22 is inserted into the inlet of the mold 24. This figure shows a state where the mold is fitted to the tundish 10 before casting. In this assembling state, the annular projection 145 assists in positioning (matching) the mold 24. Since the annular gasket 148 is fixed to the outer circumferential surface of the flange 25 rather than the end surface of the mold, the annular gasket 148 is not detached before the engagement of the tundish 10 and the mold 24 is completed. Moreover, the fixed annular gasket 148 can absorb a change in pressure of the contact surface caused by a difference in dimensional error and a joining dimension of the connecting member and thermal expansion or other causes. The intermediate ring 18 shown in FIG. 1 is highly breathable because it is made of zircon or other refractory materials. In addition, the pressure in the mold 24 becomes negative or lower than atmospheric when the casting part is ejected as described above.

For this reason, air is sucked into it through the opening in the intermediate ring 18.

FIG. 14 shows a device for preventing air from flowing into the mold 24 by covering part of the intermediate ring 18. The annular stainless steel foil 151 is bonded to the mold side end surface 18a of the intermediate ring 18 with the annular gasket 150 inside.

The thickness of the stainless steel foil 151 is 50 μm. In order to prevent the annular gasket 150 from being overheated by heat conducted from the stainless steel foil 151, the outer diameter of the stainless foil 151 is smaller than the inner diameter of the annular gasket 150. This sealing device is characterized by high airtightness between the sliding gate 15 and the tundish-side end surface 18b of the intermediate ring 18 and the flow of air from the outer circumferential surface 18c. Used when suppressed by thick parts.

The annular stainless steel foil 151 prevents air from flowing into the blocking space 51 enclosed by the annular gasket 150 from the relatively thin portion of the intermediate ring 18 member.

FIG. 15 shows another embodiment in which air flows into the mold 24 by covering the outer surface of the intermediate ring 18. The mold end surface 18a, the tundish end surface 18b, and the outer circumferential surface 18c of the intermediate ring 18 are covered with a stainless steel foil 153.

This sealing device is used when the intermediate ring 18 member is highly breathable and is not exposed to temperatures above the limit temperature that the annular gasket 150 can withstand.

When the annular gasket 150 is tightly sealed to the outer circumference of the flange 19 of the intermediate ring 18, the tundish end surface 18b and the outer circumferential surface 18c of the intermediate ring 18 are made of stainless steel. It may be covered with foil 151.

In all the embodiments described so far, the molds are arranged horizontally, while those shown in FIG. 16 are arranged vertically. The inner surface of the outer frame 161 of the intermediate ring 158 is tightly fixed to the outer surface of its flange 159, while the bottom surface of the outer frame 161 of the intermediate ring 158 is the mold 166. It is fixed in close contact with the inlet end surface.

The annular space 168 which is not sealed by the gasket is provided between the flange 159 of the intermediate ring 158 and the inlet end surface of the mold 166. The nitrogen gas supply port 162 provided in the outer frame 161 of the intermediate ring 158 is connected to the annular space 168.

As in the preferred embodiment described above, nitrogen gas whose pressure is controlled at about 6-10 kgf / cm 2 is supplied to the annular space 168 to prevent air from flowing into the mold 166. FIG. 16 shows a state immediately after the solidification shell S is detached from the end surface of the brake ring 164 as a result of the intermittent withdrawal of the casting part.

Table 1 shows the results of the casting of 170 mm diameter round billet of various types of steel under various casting conditions of the horizontal continuous casting machine shown in FIG.

The casting part intermittently exits at intervals of 0.5 seconds with an oscillation width of 15 mm and an average exit speed of 1.8 m / min.

As is apparent from Table 1, the number of bubbles formed by the continuous casting method of the present invention is 3.6% or less, which is a much smaller value than the number of bubbles by the conventional method.

The continuous casting method of the present invention does not form more than 10 bubbles per 500 cm 2.

As such, it is not necessary to remove a small number of bubbles from the casting part.

Claims (34)

Continuously supplying molten metal from the tundish 10 to a cooling mold 24 having an inlet and an outlet through at least a brake ring 22 in contact with the inlet of the mold 24; Continuously cooling the molten metal M in the mold 24 to start the solidification of the molten metal under the surface of the molten metal to form the casting part C; In the continuous casting method comprising the step of intermittently withdrawing the casting portion (C) with respect to the mold (24) through the outlet of the mold, the mold 24 is a closed gas soluble in the molten metal (M) pressure is more than atmospheric pressure Continuous casting method, characterized in that uniformly supplied from the inlet of the mold 24 to the whole contact area of the brake ring (22). Continuously supplying molten metal from the tundish 10 to a cooling mold 24 having an inlet and an outlet through at least a brake ring 22 in contact with the inlet of the mold 24; Continuously cooling the molten metal M in the mold 24 to start the solidification of the molten metal under the surface of the molten metal to form the casting part C; In the continuous casting method comprising the step of intermittently withdrawing the casting portion (C) with respect to the mold (24) through the outlet of the mold, the air 24 through the contact area of the mold 24 and the brake ring 22 Penetration into the mold) is prevented by installing a blocking space (36) surrounded by a closed curve whose diameter is larger than the maximum diameter of the contact area by the inlet portion of the mold (24); A continuous casting method, characterized in that the pressure is above atmospheric pressure and soluble in the molten metal (M) is constantly supplied into the blocking space (36). Continuously supplying molten metal from the tundish 10 to a cooling mold 24 having an inlet and an outlet through at least a brake ring 22 in contact with the inlet of the mold 24; Continuously cooling the molten metal M in the mold 24 to start the solidification of the molten metal under the surface of the molten metal to form the casting part C; In the continuous casting method comprising the step of intermittently withdrawing the casting portion (C) with respect to the mold (24) through the outlet of the mold, the air 24 through the contact area of the mold 24 and the brake ring 22 The first blocking space (95) surrounded by the closed curve larger than the maximum diameter of the contact area of the mold (24) and the brake ring (22) and the first blocking space isolated from the second blocking space. Preventing the second blocking space 111 including the blocking space therein by the side of the inlet of the mold 24; Continuous casting is characterized in that the pressure in the first blocking space (95) is maintained below the atmospheric pressure, and the pressure is above the atmospheric pressure and the closed gas soluble in the molten metal (M) is constantly supplied into the second blocking space (111). Way. Continuously supplying molten metal from the tundish 10 to a cooling mold 24 having an inlet and an outlet through at least a brake ring 22 in contact with the inlet of the mold 24; Continuously cooling the molten metal M in the mold 24 to start the solidification of the molten metal under the surface of the molten metal to form the casting part C; In the continuous casting method comprising the step of intermittently withdrawing the casting portion (C) with respect to the mold (24) through the outlet of the mold, the mold 24 is a closed gas soluble in the molten metal (M) pressure is more than atmospheric pressure And continuously supplying the entire space between the inner surface of the mold (24) and the outer surface of the casting portion (C) from the outlet portion of the mold. Continuously supplying molten metal from the tundish 10 to a cooling mold 24 having an inlet and an outlet through at least a brake ring 22 in contact with the inlet of the mold 24; Continuously cooling the molten metal M in the mold 24 to start the solidification of the molten metal under the surface of the molten metal to form the casting part C; In the continuous casting method comprising the step of intermittently withdrawing the casting portion (C) with respect to the mold (24) through the outlet of the mold, the infiltration of air into the mold (24) than the diameter of the mold (24) Preventing the blocking space 36 surrounded by the large closed curve from being installed next to the outlet of the mold 24; A continuous casting method, characterized in that the pressure is above atmospheric pressure and the closed gas soluble in the molten metal (M) is constantly supplied to the blocking space (36). Continuously supplying molten metal from the tundish 10 to a cooling mold 24 having an inlet and an outlet through at least a brake ring 22 in contact with the inlet of the mold 24; Continuously cooling the molten metal M in the mold 24 to start the solidification of the molten metal under the surface of the molten metal to form the casting part C; In the continuous casting method comprising the step of intermittently withdrawing the casting portion (C) with respect to the mold (24) through the outlet of the mold, the mold 24 is a closed gas soluble in the molten metal (M) pressure is more than atmospheric pressure From the inlet of the mold to the entire contact area between the mold 24 and the brake ring 22 and from the outlet of the mold 24 to the whole space between the inner surface of the mold 24 and the outer surface of the casting part C. The method characterized in that the constant feeding. Continuously supplying molten metal from the tundish 10 to a cooling mold 24 having an inlet and an outlet through at least a brake ring 22 in contact with the inlet of the mold 24, Continuously cooling the molten metal M in the mold 24 to start the solidification of the molten metal under the surface of the molten metal to form the casting part C; In the continuous casting method comprising the step of intermittently withdrawing the casting portion (C) with respect to the mold (24) through the outlet of the mold, the air 24 through the contact area of the mold 24 and the brake ring 22 ) Penetrating the inside by installing a blocking space 36 surrounded by a closed curve whose diameter is larger than the maximum diameter of the contact area by the inlet of the mold 24; A shielding space 36 is provided next to the outlet of the mold 24 in which air penetrates from the outlet of the mold 24 to the mold 24 by a closed curve whose diameter is larger than the inner diameter of the mold 24. Thereby preventing; A continuous casting method, characterized in that the pressure is above atmospheric pressure and soluble in the molten metal (M) is constantly supplied into the blocking space (36) at the inlet and outlet ends of the mold (24). Continuously supplying molten metal from the tundish 10 to a cooling mold 24 having an inlet and an outlet through at least a brake ring 22 in contact with the inlet of the mold 24; Continuously cooling the molten metal M in the mold 24 to start the solidification of the molten metal under the surface of the molten metal to form the casting part C; In the continuous casting method comprising the step of intermittently withdrawing the casting portion (C) with respect to the mold (24) through the outlet of the mold, the air 24 through the contact area of the mold 24 and the brake ring 22 Penetration into the mold) by installing a blocking space 36, which is surrounded by a closed curve whose diameter is larger than the maximum diameter of the contact area, beside the inlet of the mold 24; Preventing air from penetrating into the mold from the outlet of the mold 24 by providing a blocking space 36 surrounded by a closed curve whose diameter is larger than the inner diameter of the mold 24 beside the outlet of the mold 24; The pressure in the blocking space 36 at the inlet end of the mold 24 is kept below atmospheric pressure, and the blocking space at the outlet end of the mold 24 contains a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal M. (36) A continuous casting method characterized in that the supply is constant. Continuously supplying molten metal from the tundish 10 to a cooling mold 24 having an inlet and an outlet through at least a brake ring 22 in contact with the inlet of the mold 24; Continuously cooling the molten metal M in the mold 24 to start the solidification of the molten metal under the surface of the molten metal to form the casting part C; In the continuous casting method comprising the step of intermittently withdrawing the casting portion (C) with respect to the mold (24) through the outlet of the mold, the air 24 through the contact area of the mold 24 and the brake ring 22 The first barrier is isolated from the first blocking space 95 and the second blocking space surrounded by a closed curve whose diameter is larger than the maximum diameter of the contact area between the mold 24 and the brake ring 22. Preventing the second blocking space 111, which includes the space therein, next to the inlet of the mold; The pressure in the first blocking space 95 is kept below atmospheric pressure; Constant pressure is supplied into the second shut-off space 111 whose pressure is above atmospheric pressure and soluble in the molten metal M; The infiltration of air from the outlet of the mold 24 into the mold 24 is provided by installing a blocking space 36 next to the outlet of the mold 24 surrounded by a closed curve whose diameter is larger than the inner diameter of the mold 24. Prevent; A continuous casting method characterized by supplying a closed gas (36) at the outlet end of the mold (24) with a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal (M). The method according to claim 1, wherein nitrogen gas is used as a closed gas. At least at the inlet of the mold 24 while forming the casting part C by continuously cooling the molten metal M and causing solidification of the molten metal M under the surface of the molten metal in the mold 24. The casting part C is connected to the tundish 10 through a brake ring 22 connected to the cooling mold 24 having an inlet part and an outlet part, and a casting part C with respect to the mold 24 through the outlet part of the mold. In the continuous casting device composed of an apparatus 56 for intermittently discharging), a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal M is formed from the inlet of the mold 24 and the mold 24. And a device (40) for uniformly supplying the entire contact area of the brake ring (22). At least at the inlet of the mold 24 while forming the casting part C by continuously cooling the molten metal M and causing solidification of the molten metal M under the surface of the molten metal in the mold 24. The casting part C is connected to the tundish 10 through a brake ring 22 connected to the cooling mold 24 having an inlet part and an outlet part, and a casting part C with respect to the mold 24 through the outlet part of the mold. In the continuous casting device composed of a device 56 for intermittently discharging), the inlet end of the mold 24 has a diameter larger than the maximum diameter of the contact area between the mold 24 and the brake ring 22. An annular sealing device provided at the inlet to form a blocking space 36 at an inlet of the mold 24 to prevent air from penetrating into the mold 24 through the contact area; And a device (40) for constantly supplying a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal (M) to the blocking space (36). At least at the inlet of the mold 24 while forming the casting part C by continuously cooling the molten metal M and causing solidification of the molten metal M under the surface of the molten metal in the mold 24. The casting part C is connected to the tundish 10 through a brake ring 22 connected to the cooling mold 24 having an inlet part and an outlet part, and a casting part C with respect to the mold 24 through the outlet part of the mold. In the continuous casting device composed of a device 56 for intermittently discharging), the inlet end of the mold 24 has a diameter larger than the maximum diameter of the contact area between the mold 24 and the brake ring 22. A first annular sealing device installed in the first annular sealing device to form a first blocking space 95 at an inlet of the mold 24 to prevent air from penetrating into the mold 24 through the contact area; A second annular sealing device including a first blocking space 95 and installed at an inlet of the mold 24 and forming a second blocking space 111 isolated from the first blocking space 95; A device for maintaining the pressure in the first blocking space (95) below atmospheric pressure; And a device (40) for constantly supplying a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal (M) to the secondary blocking space (111). At least at the inlet of the mold 24 while forming the casting part C by continuously cooling the molten metal M and causing solidification of the molten metal M under the surface of the molten metal in the mold 24. The casting part C is connected to the tundish 10 through a brake ring 22 connected to the cooling mold 24 having an inlet part and an outlet part, and a casting part C with respect to the mold 24 through the outlet part of the mold. In the continuous casting device composed of a device 56 for intermittently discharging), a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal M is transferred from the outlet of the mold 24 to the mold 24. Continuous casting apparatus characterized in that it comprises a device 40 for uniformly supplying the entire space between the inner surface and the outer surface of the casting portion (C). At least at the inlet of the mold 24 while forming the casting part C by continuously cooling the molten metal M and causing solidification of the molten metal M under the surface of the molten metal in the mold 24. The casting part C is connected to the tundish 10 through a brake ring 22 connected to the cooling mold 24 having an inlet part and an outlet part, and a casting part C with respect to the mold 24 through the outlet part of the mold. In the continuous casting device composed of the device 56 for intermittently discharging), has a diameter larger than the inner diameter of the mold 24, is provided at the outlet end of the mold 24, the air is An annular outlet end sealing device (44) which forms an outlet end blocking space (51) at the outlet of the mold (24) to prevent penetration from the tapping into the mold (24); And a device (40) for constantly supplying a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal (M) into the blocking space (51) at the outlet end of the mold. At least at the inlet of the mold 24 while forming the casting part C by continuously cooling the molten metal M and causing solidification of the molten metal M under the surface of the molten metal in the mold 24. The casting part C is connected to the tundish 10 through a brake ring 22 connected to the cooling mold 24 having an inlet part and an outlet part, and a casting part C with respect to the mold 24 through the outlet part of the mold. In the continuous casting device composed of an apparatus 56 for intermittently discharging), a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal M is formed from the inlet of the mold 24 and the mold 24. A device 40 which is constantly supplied throughout the contact area of the brake ring 22; And a constant supply of a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal (M) from the outlet of the mold 24 to the entire space between the inner surface of the mold 24 and the outer surface of the casting part C. Continuous casting apparatus comprising a device for. At least at the inlet of the mold 57 while forming the casting part C by continuously cooling the molten metal M and causing solidification of the molten metal M under the surface of the molten metal in the mold 57. The casting part C is connected to the tundish 10 through the brake ring 22 connected thereto, and the casting part C is connected to the mold 57 through the cooling mold 57 having the inlet part and the outlet part, and the outlet part of the mold. In the continuous casting device composed of a device 56 for intermittently discharging), the inlet end of the mold 57 has a diameter larger than the maximum diameter of the contact area between the mold 57 and the brake ring 22. An annular inlet end sealing device (34) formed at the inlet and forming an inlet end blocking space (36) at the inlet of the mold (57) to prevent air from penetrating into the mold (57) through the contact area; An apparatus 40 for constantly supplying a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal M into the blocking space 36 at the inlet of the mold 57; It has a diameter larger than the inner diameter of the mold 57, and is provided at the outlet end of the mold 57, to prevent air from penetrating into the mold 57 through the outlet of the mold 57 An annular outlet end closure device 44 for forming an outlet end blocking space 51 at an outlet portion of the outlet; And a device (40) for constantly supplying a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal (M) into the blocking space (51) at the outlet of the mold (57). At least at the inlet of the mold 24 while allowing the molten metal M to be continuously cooled and solidification of the molten metal M started under the surface of the molten metal in the mold 57. The casting part C is connected to the tundish 10 through the brake ring 22 connected thereto, and the casting part C is connected to the mold 57 through the cooling mold 57 having the inlet part and the outlet part, and the outlet part of the mold. In the continuous casting device composed of a device 56 for intermittently discharging), the inlet end of the mold 57 has a diameter larger than the maximum diameter of the contact area between the mold 57 and the brake ring 22. An annular inlet end closure device 94 formed at the inlet end blocking space 95 at an inlet of the mold 57 to prevent air from penetrating into the mold 57 through the contact area; Pressure in the inlet end blocking space 95 is below atmospheric pressure Apparatus 104 for maintaining the system; It has a diameter larger than the inner diameter of the mold 57, and is provided at the outlet end of the mold 57, in order to prevent air from penetrating into the mold 57 through the outlet of the mold 57, Annular outlet end sealing device for forming an outlet end blocking space at the outlet of the; And a device (40) for constantly supplying a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal (M) to the blocking space at the outlet of the mold (57). At least at the inlet of the mold 24 while allowing the molten metal M to be continuously cooled and solidification of the molten metal M started under the surface of the molten metal in the mold 57. The casting part C is connected to the tundish 10 through the brake ring 22 connected thereto, and the casting part C is connected to the mold 57 through the cooling mold 57 having the inlet part and the outlet part, and the outlet part of the mold. In the continuous casting device constituted by the device 56 for intermittently discharging), the inlet of the mold 57 has a diameter larger than the maximum diameter of the contact area between the mold 57 and the brake ring 22. A first annular sealing device 94 provided at an end and forming a first blocking space 95 at an inlet of the mold 57 to prevent air from penetrating into the mold 57 through the contact area; ; A second annular sealing device including a first blocking space (95) and installed in the inlet of the mold (57) and forming a second blocking space (111) isolated from the first blocking space (95). (106, 109); An apparatus (104) for maintaining a pressure in the first blocking space (95) below atmospheric pressure; Apparatus 40 for constantly supplying a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal M into the second blocking space 111, has a diameter larger than the inner diameter of the mold 57, and the mold 57 An annular outlet end closure device provided at the outlet end of the mold and forming an outlet end blocking space at the outlet of the mold 57 to prevent air from penetrating into the mold 57 through the outlet of the mold 57 ( 118); And a device (40) for constantly supplying a closed gas whose pressure is above atmospheric pressure and soluble in the molten metal (M) into the blocking space at the outlet of the mold (57). 12. A continuous casting apparatus according to claim 11, wherein the mold (24, 57, 61) is arranged such that its axis extends horizontally. 12. The mold according to claim 11, wherein the mold consisting of the first mold (57) and the second mold (61) connected to the outlet of the first mold (57), air is formed through two molds. The intermediate sealing device is formed between the first mold 57 and the second mold 61 and forms an intermediate blocking space between the first mold 57 and the second mold 61 to prevent penetration into the mold. (116) and a device (40) for constantly supplying a closed gas soluble in the molten metal (M) into the intermediate blocking space whose pressure is above atmospheric pressure. 22. The continuous casting apparatus according to claim 21, wherein the second mold (61) consists of a plurality of mold members (62) in which the second mold (61) is movable in the radial direction. 12. A continuous casting apparatus according to claim 11, wherein an annular gasket made of silicone rubber is used as the sealing device (34, 94, 109, 116). The continuous casting apparatus according to claim 11, wherein nitrogen gas is used as a closed gas. 14. A continuous casting apparatus according to claim 13, wherein a vacuum pump (104) connected to the blocking space (95) through a pipe is used as a device for maintaining the pressure of the blocking space (95) below atmospheric pressure. 12. The intermediate ring (18, 84, 141) in contact with the brake ring (22) is also inserted between the interconnected tundish (10) and the mold (24, 57). Continuous casting device. 27. The continuous space as claimed in claim 26, wherein the blocking space (36) is formed by inserting an annular gasket (34) between the intermediate ring (18) and the inlet end surface of the mold (24) in a manner surrounding the brake ring. Casting equipment. 27. The hollow annular cooling ring (88) provided along the circumference of the intermediate ring (84), between the hollow cooling ring (88) surrounding the brake ring (22) and the inlet end surface of the mold (57). An annular gasket (94) inserted into and forming a blocking space (95), and a continuous casting device comprising a device (91) for supplying cooling air to the hollow cooling ring (88). 28. The outlet end surface of the intermediate ring 141 in the inner side of the annular gasket 139 according to claim 27, wherein the circumferential groove 142 that checks the temperature rise of the annular gasket 139 and is concentric with the intermediate ring 141. Continuous casting apparatus, characterized in that provided in. 12. The brake ring (22) according to claim 11, wherein the brake ring (22) is held in contact with the nozzle of the tundish (10) at the outlet end of the tundish (10) while the gasket is disposed between the brake ring and the tundish. The annular protrusion 145 concentric with the nozzle of 10 is formed in the steel shell 11 at the outlet end of the tundish 10, and is provided with an annular gasket groove provided in the circumference of the flange of the mold 24. 147 is inserted into the annular gasket 148 is a continuous casting device, characterized in that to form a blocking space by contacting the inner circumferential surface of the annular projection (145). 13. The circumferential wall (106) is provided between the tundish (10) and the mold (57), and the concentric double wall (107) is formed to form the blocking space (36, 95, 111). It is installed to face the wall 106, the gasket 109 is inserted into the groove 108 formed by the double wall 107, the sealing device of the circumferential wall 106 in contact with the gasket 109 Continuous casting device, characterized in that formed by the tip. 32. A continuous casting apparatus according to claim 31, wherein one of the tundish (10) and the mold (24, 57, 61) is fixed and the other is movable in the direction in which the casting part (C) is withdrawn. 28. The continuous casting apparatus as claimed in claim 27, wherein the inside of the annular gasket (150) at the front end surface of the intermediate ring (18) is covered with a sealing material (151). 28. A continuous casting apparatus according to claim 27, which is covered with at least the sealing member (153) of the intermediate ring (18).